Showing papers in "International Journal of Cancer in 2008"
TL;DR: The analysis of heterogeneity showed that study type, gender and adjustment for confounding factors significantly influence the RRs estimates and the reliability of the studies, and pooled RRs for respiratory cancers were greater than the pooled estimates for other sites.
Abstract: We conducted a systematic meta-analysis of observational studies on cigarette smoking and cancer from 1961 to 2003. The aim was to quantify the risk for 13 cancer sites, recognized to be related to tobacco smoking by the International Agency for Research on Cancer (IARC), and to analyze the risk variation for each site in a systematic manner. We extracted data from 254 reports published between 1961 and 2003 (177 case-control studies, 75 cohorts and 2 nested case-control studies) included in the 2004 IARC Monograph on Tobacco Smoke and Involuntary Smoking. The analyses were carried out on 216 studies with reported estimates for 'current' and/or 'former' smokers. We performed sensitivity analysis, and looked for publication and other types of bias. Lung (RR = 8.96; 95% CI: 6.73-12.11), laryngeal (RR = 6.98; 95% CI: 3.14-15.52) and pharyngeal (RR = 6.76; 95% CI: 2.86-15.98) cancers presented the highest relative risks (RRs) for current smokers, followed by upper digestive tract (RR = 3.57; 95% CI: 2.63-4.84) and oral (RR = 3.43; 95% CI: 2.37-4.94) cancers. As expected, pooled RRs for respiratory cancers were greater than the pooled estimates for other sites. The analysis of heterogeneity showed that study type, gender and adjustment for confounding factors significantly influence the RRs estimates and the reliability of the studies.
781 citations
TL;DR: The pharmacological properties of azanucleosides and their interactions with various cellular pathways are examined and an understanding of the cellular mechanisms mediating transmembrane transport and metabolic activation will be critically important for optimizing patient responses.
Abstract: The cytosine analogues 5-azacytosine (azacytidine) and 2'-deoxy-5-azacytidine (decitabine) are the currently most advanced drugs for epigenetic cancer therapies. These compounds function as DNA methyltransferase inhibitors and have shown substantial potency in reactivating epigenetically silenced tumor suppressor genes in vitro. However, it has been difficult to define the mode of action of these drugs in patients and it appears that clinical responses are influenced both by epigenetic alterations and by apoptosis induction. To maximize the clinical efficacy of azacytidine and decitabine it will be important to understand the molecular changes induced by these drugs. In this review, we examine the pharmacological properties of azanucleosides and their interactions with various cellular pathways. Because azacytidine and decitabine are prodrugs, an understanding of the cellular mechanisms mediating transmembrane transport and metabolic activation will be critically important for optimizing patient responses. We also discuss the mechanism of DNA methyltransferase inhibition and emphasize the need for the identification of predictive biomarkers for the further advancement of epigenetic therapies.
767 citations
TL;DR: It is concluded that KS and NHL incidence declined markedly in recent years, likely reflecting HAART‐related improvements in immunity, while incidence of some non‐AIDS‐defining cancers increased, leading to a shift in the spectrum of cancer among HIV‐infected persons.
Abstract: Data are limited regarding cancer risk in human immunodeficiency virus (HIV)-infected persons with modest immunosuppression, before the onset of acquired immunodeficiency syndrome (AIDS). For some cancers, risk may be affected by highly active antiretroviral therapy (HAART) widely available since 1996. We linked HIV/AIDS and cancer registries in Colorado, Florida and New Jersey. Standardized incidence ratios (SIRs) compared cancer risk in HIV-infected persons (initially AIDS-free) during the 5-year period after registration with the general population. Poisson regression was used to compare incidence across subgroups, adjusting for demographic factors. Among 57,350 HIV-infected persons registered during 1991-2002 (median CD4 count 491 cells/mm(3)), 871 cancers occurred during follow-up. Risk was elevated for Kaposi sarcoma (KS, SIR 1,300 [n = 173 cases]), non-Hodgkin lymphoma (NHL, 7.3 [n = 203]), cervical cancer (2.9 [n = 28]) and several non-AIDS-defining malignancies, including Hodgkin lymphoma (5.6 [n = 36]) and cancers of the lung (2.6 [n = 109]) and liver (2.7 [n = 14]). KS and NHL incidence declined over time but nonetheless remained elevated in 1996-2002. Incidence increased in 1996-2002 compared to 1991-1995 for Hodgkin lymphoma (relative risk 2.7, 95%CI 1.0-7.1) and liver cancer (relative risk infinite, one-sided 95%CI 1.1-infinity). Non-AIDS-defining cancers comprised 31.4% of cancers in 1991-1995, versus 58.0% in 1996-2002. For KS and NHL, risk was inversely related to CD4 count, but these associations attenuated after 1996. We conclude that KS and NHL incidence declined markedly in recent years, likely reflecting HAART-related improvements in immunity, while incidence of some non-AIDS-defining cancers increased. These trends have led to a shift in the spectrum of cancer among HIV-infected persons.
722 citations
TL;DR: Fibrosis is a major side effect of radiotherapy, and the question how the main methods of cancer management, including chemotherapy, hormonotherapy and surgery affect myofibroblasts and by inference the surrogate endpoints invasion and metastasis is addressed.
Abstract: Tissue integrity is maintained by the stroma in physiology. In cancer, however, tissue invasion is driven by the stroma. Myofibroblasts and cancer-associated fibroblasts are important components of the tumor stroma. The origin of myofibroblasts remains controversial, although fibroblasts and bone marrow-derived precursors are considered to be the main progenitor cells. Myofibroblast reactions also occur in fibrosis. Therefore, we wonder whether nontumorous myofibroblasts have different characteristics and different origins as compared to tumor-associated myofibroblasts. The mutual interaction between cancer cells and myofibroblasts is dependent on multiple invasive growth-promoting factors, through direct cell-cell contacts and paracrine signals. Since fibrosis is a major side effect of radiotherapy, we address the question how the main methods of cancer management, including chemotherapy, hormonotherapy and surgery affect myofibroblasts and by inference the surrogate endpoints invasion and metastasis.
690 citations
TL;DR: The findings suggest that miR‐15b and miR-16 could play a role in the development of MDR in gastric cancer cells at least in part by modulation of apoptosis via targeting BCL2.
Abstract: microRNAs are endogenous small noncoding RNAs that regulate gene expression negatively at posttranscriptional level. This latest addition to the complex gene regulatory circuitry revolutionizes our way to understanding physiological and pathological processes in the human body. Here we investigated the possible role of microRNAs in the development of multidrug resistance (MDR) in gastric cancer cells. microRNA expression profiling revealed a limited set of microRNAs with altered expression in multidrug- resistant gastric cancer cell line SGC7901/VCR compared to its parental SGC7901 cell line. Among the downregulated microRNAs are miR-15b and miR-16, members of miR-15/16 family, whose expression was further validated by qRT-PCR. In vitro drug sensitivity assay demonstrated that overexpression of miR-15b or miR-16 sensitized SGC7901/VCR cells to anticancer drugs whereas inhibition of them using antisense oligonucleotides conferred SGC7901 cells MDR. The downregulation of miR-15b and miR-16 in SGC7901/VCR cells was concurrent with the upregulation of Bcl-2 protein. Enforced mir-15b or miR-16 expression reduced Bcl-2 protein level and the luciferase activity of a BCL2 3′ untranslated region-based reporter construct in SGC7901/VCR cells, suggesting that BCL2 is a direct target of miR-15b and miR-16. Moreover, overexpression of miR-15b or miR-16 could sensitize SGC7901/VCR cells to VCR-induced apoptosis. Taken together, our findings suggest that miR-15b and miR-16 could play a role in the development of MDR in gastric cancer cells at least in part by modulation of apoptosis via targeting BCL2. © 2008 Wiley-Liss, Inc.
669 citations
TL;DR: It is shown that CD133 negative glioma cells are tumorgenic in nude rats, and thatCD133 positive cells can be obtained from these tumors, suggesting that it may be involved during brain tumor progression.
Abstract: CD133 is a cell surface marker expressed on progenitors of haematopoietic and endothelial cell lineages. Moreover, several studies have identified CD133 as a marker of brain tumor-initiating cells. In this study, human glioblastoma multiforme biopsies were engrafted intracerebrally into nude rats. The resulting tumors were serially passaged in vivo, and monitored by magnetic resonance imaging. CD133 expression was analyzed at various passages. Tumors initiated directly from the biopsies expressed little or no CD133, and showed no contrast enhancement suggesting an intact blood-brain barrier. During passaging, the tumors gradually displayed more contrast enhancement, increased angiogenesis and a shorter survival. Real-time qPCR and immunoblots showed that this was accompanied by increased CD133 expression. Primary biopsy spheroids and xenograft tumors were subsequently dissociated and flow sorted into CD133 negative and CD133 positive cell populations. Both populations incorporated BrdU in cell culture, and expressed the neural precursor marker nestin. Notably, CD133 negative cells derived from 6 different patients were tumorgenic when implanted into the rat brains. For 3 of these patients, analysis showed that the resulting tumors contained CD133 positive cells. In conclusion, we show that CD133 negative glioma cells are tumorgenic in nude rats, and that CD133 positive cells can be obtained from these tumors. Upon passaging of the tumors in vivo, CD133 expression is upregulated, coinciding with the onset of angiogenesis and a shorter survival. Thus, our findings do not suggest that CD133 expression is required for brain tumor initiation, but that it may be involved during brain tumor progression.
573 citations
TL;DR: Urologic tract cancer and ovarian cancer occur frequently enough in some LS subgroups to justify trials to evaluate promising prevention interventions, and other cancer types studied occur too infrequently to justify strenuous cancer control interventions.
Abstract: Persons with the Lynch syndrome (LS) are at high risk for cancer, including cancers of the small bowel, stomach, upper urologic tract (renal pelvis and ureter), ovary, biliary tract and brain tumors, in addition to the more commonly observed colorectal and endometrial cancers. Cancer prevention strategies for these less common cancers require accurate, age-specific risk estimation. We pooled data from 4 LS research centers in a retrospective cohort study, to produce absolute incidence estimates for these cancer types, and to evaluate several potential risk modifiers. After elimination of 135 persons missing crucial information, cohort included 6,041 members of 261 families with LS-associated MLH1 or MSH2 mutations. All were either mutation carriers by test, probable mutation carriers (endometrial/colorectal cancer-affected), or first-degree relatives of these. Among mutation carriers and probable carriers, urologic tract cancer (N = 98) had an overall lifetime risk (to age 70) of 8.4% (95% CI: 6.6-10.8); risks were higher in males (p < 0.02) and members of MSH2 families (p < 0.0001). Ovarian cancer (N = 72) had an lifetime risk of 6.7% (95% CI: 5.3-9.1); risks were higher in women born after the median year of birth (p < 0.008) and in members of MSH2 families (p < 0.006). Brain tumors and cancers of the small bowel, stomach, breast and biliary tract were less common. Urologic tract cancer and ovarian cancer occur frequently enough in some LS subgroups to justify trials to evaluate promising prevention interventions. Other cancer types studied occur too infrequently to justify strenuous cancer control interventions.
529 citations
TL;DR: It is revealed that TN BCs represent a more heterogeneous group than basal BCs, including basal and nonbasal tumors very different both at the histoclinical and molecular level, notably for mRNA expression of molecules targeted by specific therapies under evaluation in clinical trials.
Abstract: The basal molecular subtype of breast cancer (BC) is defined by the mRNA expression pattern of an intrinsic approximately 500-gene set It is the most homogeneous subtype in transcriptional terms, and one of the most aggressive in prognostic terms Clinical trials testing new systemic therapeutic strategies have been launched in basal BCs Although no proof of evidence has yet been reported, basal tumors are currently assimilated to and selected as triple-negative (TN) BCs in these trials because of their frequent immunohistochemical (IHC) negativity for hormone and ERBB2 receptors Here, we have assessed the degrees of correlation and of homogeneity of the TN phenotype (IHC-based definition) and the basal subtype (gene expression-based definition) We analyzed 172 TN BCs defined by gene expression profile as basal (123 cases) and nonbasal (49 cases) Conversely, 160 tumors were defined as basal by their gene expression profile and included 123 TN and 37 non-TN samples Uni- and multivariate analyses revealed that TN BCs represent a more heterogeneous group than basal BCs, including basal and nonbasal tumors very different both at the histoclinical and molecular level, notably for mRNA expression of molecules targeted by specific therapies under evaluation in clinical trials These results call for caution in the interpretation of ongoing trials and selection of patients in future trials They also warrant the identification of molecular markers for basal BCs more clinically applicable than gene expression profiles
443 citations
TL;DR: KIT signaling has a role in tumor angiogenesis of SCF‐producing H146 cells, and E7080 causes regression of H146 tumors as a result of antiangiogenic activity mediated by inhibition of both KIT and VEGF receptor signaling.
Abstract: E7080 is an orally active inhibitor of multiple receptor tyrosine kinases including VEGF, FGF and SCF receptors. In this study, we show the inhibitory activity of E7080 against SCF-induced angiogenesis in vitro and tumor growth of SCF-producing human small cell lung carcinoma H146 cells in vivo. E7080 inhibits SCF-driven tube formation of HUVEC, which express SCF receptor, KIT at the IC(50) value of 5.2 nM and it was almost identical for VEGF-driven one (IC(50) = 5.1 nM). To assess the role of SCF/KIT signaling in tumor angiogenesis, we evaluated the effect of imatinib, a selective KIT kinase inhibitor, on tumor growth of H146 cells in nude mice. Imatinib did not show the potent antitumor activity in vitro (IC(50) = 2,200 nM), because H146 cells did not express KIT. However, oral administration of imatinib at 160 mg/kg clearly slowed tumor growth of H146 cells in nude mice, accompanied by decreased microvessel density. Oral administration of E7080 inhibited tumor growth of H146 cells at doses of 30 and 100 mg/kg in a dose-dependent manner and caused tumor regression at 100 mg/kg. While anti-VEGF antibody also slowed tumor growth, it did not cause tumor regression. These results indicate that KIT signaling has a role in tumor angiogenesis of SCF-producing H146 cells, and E7080 causes regression of H146 tumors as a result of antiangiogenic activity mediated by inhibition of both KIT and VEGF receptor signaling. E7080 may provide therapeutic benefits in the treatment of SCF-producing tumors.
427 citations
TL;DR: It is revealed that smoking significantly increases the risk of cancer death from TSCC and that non‐smoking patients with HPV‐containing TSCC show a remarkably better disease‐specific survival rate, implicating the latter to be a reliable HPV biomarker.
Abstract: Oncogenic human papillomavirus (HPV) is a causative agent in a subgroup of head and neck carcinomas, particularly tonsillar squamous cell carcinomas (TSCC). This study was undertaken because controversial data exist on the physical status of HPV-DNA and the use of p16(INK4A) overexpression as surrogate HPV marker, and to examine the impact of HPV and tobacco consumption on the clinical course of TSCC. Tissue sections of 81 TSCC were analyzed by HPV 16-specific fluorescence in situ hybridization (FISH) and p16(INK4A)-specific immunohistochemistry. Results were correlated with clinical and demographic data. HPV 16 integration was detected by FISH as punctate signals in 33 out of 81 (41%) TSCC, 32 of which showed p16(INK4A) accumulation. Only 5 out of 48 HPV-negative tumors showed p16(INK4A) immunostaining (p < 0.0001). The presence of HPV furthermore correlates significantly with low tobacco (p = 0.002) and alcohol intake (p = 0.011), poor differentiation grade (p = 0.019), small tumor size (p = 0.024), presence of a local metastasis (p = 0.001) and a decreased (loco)regional recurrence rate (p = 0.039). Statistical analysis revealed that smoking significantly increases the risk of cancer death from TSCC and that non-smoking patients with HPV-containing TSCC show a remarkably better disease-specific survival rate. HPV 16 is integrated in 41% of TSCC and strongly correlates with p16(INK4A) overexpression, implicating the latter to be a reliable HPV biomarker. Patients with HPV-positive tumors show a favorable prognosis as compared to those with HPV-negative tumors, but tobacco use is the strongest prognostic indicator. These findings indicate that oncogenic processes in the tonsils of non-smokers differ from those occurring in smokers, the former being related to HPV 16 infection.
338 citations
TL;DR: Subgroup analyses showed that low SES was significantly associated with increased oral cancer risk in high and lower income‐countries, across the world, and remained when adjusting for potential behavioural confounders.
Abstract: There is uncertainty and limited recognition of the relationship between socioeconomic inequalities and oral cancer. We aimed to quantitatively assess the association between socioeconomic status (SES) and oral cancer incidence risk. A systematic review of case-control studies obtained published and unpublished estimates of the SES risk related to oral cancer. Studies were included which reported odds ratios (ORs) and corresponding 95% CIs of oral cancer with respect to SES, or if the estimates could be calculated or obtained. Meta-analyses were performed on subgroups: SES measure, age, sex, global region, development level, time-period and lifestyle factor adjustments; while sensitivity analyses were conducted based on study methodological issues. Forty-one studies provided 15,344 cases and 33,852 controls which met our inclusion criteria. Compared with individuals who were in high SES strata, the pooled ORs for the risk of developing oral cancer were 1.85 (95%CI 1.60, 2.15; n = 37 studies) for those with low educational attainment; 1.84 (1.47, 2.31; n = 14) for those with low occupational social class; and 2.41 (1.59, 3.65; n = 5) for those with low income. Subgroup analyses showed that low SES was significantly associated with increased oral cancer risk in high and lower income-countries, across the world, and remained when adjusting for potential behavioural confounders. Inequalities persist but are perhaps reducing over recent decades. Oral cancer risk associated with low SES is significant and comparable to lifestyle risk factors. Our results provide evidence to steer health policy which focus on lifestyles factors toward an integrated approach incorporating measures designed to tackle the root causes of disadvantage.
University of Toronto1, University of Haifa2, Pomeranian Medical University3, Creighton University4, University of Oslo5, Université de Montréal6, McGill University7, Erasmus University Rotterdam8, Sheba Medical Center9, Tel Aviv University10, University of British Columbia11, University of Western Ontario12, Princess Margaret Cancer Centre13, University of Pennsylvania14, Medical University of Vienna15, Harvard University16, Mayo Clinic17, Fox Chase Cancer Center18, Cincinnati Children's Hospital Medical Center19, Ohio State University20, Curie Institute21, Hamilton Health Sciences22, Clalit Health Services23, University of San Francisco24, Rambam Health Care Campus25, University of Chicago26, City of Hope National Medical Center27, Cedars-Sinai Medical Center28, University of Vermont29, University of Alberta30, University of Manitoba31, New York University32, York University33, University of Saskatchewan34, University of Texas MD Anderson Cancer Center35, University of Michigan36
TL;DR: Nearly one‐half of the women at risk for breast cancer had taken no preventive option, relying solely on screening, and there were large differences in the uptake of the different preventive options by country of residence.
Abstract: Several options for cancer prevention are available for women with a BRCA1 or BRCA2 mutation, including prophylactic surgery, chemoprevention and screening. The authors report on preventive practices in women with mutations from 9 countries and examine differences in uptake according to country. Women with a BRCA1 or BRCA2 mutation were contacted after receiving their genetic test result and were questioned regarding their preventive practices. Information was recorded on prophylactic mastectomy, prophylactic oophorectomy, use of tamoxifen and screening (MRI and mammography). Two thousand six hundred seventy-seven women with a BRCA1 or BRCA2 mutation from 9 countries were included. The follow-up questionnaire was completed a mean of 3.9 years (range 1.5-10.3 years) after genetic testing. One thousand five hundred thirty-one women (57.2%) had a bilateral prophylactic oophorectomy. Of the 1,383 women without breast cancer, 248 (18.0%) had had a prophylactic bilateral mastectomy. Among those who did not have a prophylactic mastectomy, only 76 women (5.5%) took tamoxifen and 40 women (2.9%) took raloxifene for breast cancer prevention. Approximately one-half of the women at risk for breast cancer had taken no preventive option, relying solely on screening. There were large differences in the uptake of the different preventive options by country of residence. Prophylactic oophorectomy is now generally accepted by women and their physicians as a cancer preventive measure. However, only the minority of women with a BRCA1 or BRCA2 mutation opt for prophylactic mastectomy or take tamoxifen for the prevention of hereditary breast cancer. Approximately one-half of women at risk for breast cancer rely on screening alone.
TL;DR: CCL17 and CCL22 within the tumor are related to the increased population of Foxp3+ Tregs, with such an observation occurring in early gastric cancer.
Abstract: It has been reported that an increased population of regulatory T cells (Tregs) is one of the reasons for impaired anti-tumor immunity. Recently, Foxp3 has been reported as a reliable marker of Tregs. The authors investigated the frequency of Foxp3(+) Tregs within CD4(+) cells in TILs, regional lymph nodes and PBLs of gastric cancer patients (n = 45). Furthermore, to elucidate the mechanisms behind Treg accumulation within tumors, they evaluated the relationship between CCL17 or CCL22 expression and the frequency of Foxp3(+) Tregs in gastric cancer. CD4(+)CD25(+)Foxp3(+) Tregs as a percentage of CD4(+) cells were counted by flow cytometry and evaluated by immunohistochemistry. Moreover, an in vitro migration assay using Tregs derived from gastric cancers was performed in the presence of CCL17 or CCL22. As a result, the frequency of Foxp3(+) Tregs in TILs was significantly higher than that in normal gastric mucosa (12.4% +/- 7.5% vs. 4.1% +/- 5.3%, p < 0.01). Importantly, the increase in Tregs in TILs occurred to the same extent in early and advanced disease. Furthermore, the frequency of CCL17(+) or CCL22(+) cells among CD14(+) cells within tumors was significantly higher than that of normal gastric mucosa, and there was a significant correlation between the frequency of CCL17(+) or CCL22(+) cells and Foxp3(+) Tregs in TILs. In addition, the in vitro migration assay indicated that Tregs were significantly induced to migrate by CCL17 or CCL22. In conclusion, CCL17 and CCL22 within the tumor are related to the increased population of Foxp3(+) Tregs, with such an observation occurring in early gastric cancer.
TL;DR: Evidence is provided that some MC1R variants are associated both with melanoma and phenotype, while other are only associated with melanomas development, suggesting that MC1r variants could play a role in melanoma development both via pigmentary and non‐pigmentary pathways.
Abstract: Melanocortin-1-receptor (MC1R) is one of the major genes that determine skin pigmentation. MC1R variants were suggested to be associated with red hair, fair skin, and an increased risk of melanoma. We performed a meta-analysis on the association between the 9 most studied MC1R variants (p.V60L, p.D84E, p.V92M, p.R142H, p.R151C, p.I155T, p.R160W, p.R163Q and p.D294H) and melanoma and/or red hair, fair skin phenotype. Eleven studies on MC1R and melanoma, and 9 on MC1R and phenotype were included in the analysis. The 7 variants p.D84E, p.R142H, p.R151C, p.I155T, p.R160W, p. R163Q and p.D294H were significantly associated with melanoma development, with ORs (95%CI) ranging from 1.42 (1.09-1.85) for p.R163Q to 2.45 (1.32-4.55) for p.I155T. The MC1R variants p.R160W and p.D294H were associated both with red hair and fair skin, while p.D84E, p.R142H, and p.R151C were strongly associated with red hair only- ORs (95%CI) ranged from 2.99 (1.51-5.91) for p.D84E to 8.10 (5.82-11.28) for p.R151C. No association with melanoma or phenotype was found for p.V60L and p.V92M variants. In conclusion this meta-analysis provided evidence that some MC1R variants are associated both with melanoma and phenotype, while other are only associated with melanoma development. These results suggest that MC1R variants could play a role in melanoma development both via pigmentary and non-pigmentary pathways.
TL;DR: This review provides the first systematically reviewed evidence that antioxidant supplementation during chemotherapy holds potential for reducing dose‐limiting toxicities, however, well‐designed studies evaluating larger populations of patients given specific antioxidants defined by dose and schedule relative to chemotherapy are warranted.
Abstract: Much debate has focused on whether antioxidants interfere with the efficacy of cancer chemotherapy. The objective of this study is to systematically review the randomized, controlled clinical trial evidence evaluating the effects of concurrent use of antioxidants with chemotherapy on toxic side effects. We performed a search of literature from 1966-October 2007 using MEDLINE, Cochrane, CinAhl, AMED, AltHealthWatch and EMBASE databases. Randomized, controlled clinical trials reporting antioxidant-based mitigation of chemotherapy toxicity were included in the final tally. Searches were performed following a standardized protocol for systematic reviews. Only 33 of 965 articles considered, including 2,446 subjects, met the inclusion criteria. Antioxidants evaluated were: glutathione (11), melatonin (7), vitamin A (1), an antioxidant mixture (2), N-acetylcysteine (2), vitamin E (5), selenium (2), L-carnitine (1), Co-Q10 (1) and ellagic acid (1). The majority (24) of the 33 studies included reported evidence of decreased toxicities from the concurrent use of antioxidants with chemotherapy. Nine studies reported no difference in toxicities between the 2 groups. Only 1 study (vitamin A) reported a significant increase in toxicity in the antioxidant group. Five studies reported the antioxidant group completed more full doses of chemotherapy or had less-dose reduction than control groups. Statistical power and poor study quality were concerns with some studies. This review provides the first systematically reviewed evidence that antioxidant supplementation during chemotherapy holds potential for reducing dose-limiting toxicities. However, well-designed studies evaluating larger populations of patients given specific antioxidants defined by dose and schedule relative to chemotherapy are warranted.
TL;DR: This review will focus on bone marrow (BM) as the main tumor entities in Europe and the United States and present currently available methods for the detection and characterization of disseminated tumor cells (DTC).
Abstract: The prognosis of cancer patients is largely determined by the occurrence of distant metastases. In patients with primary tumors, this relapse is mainly due to clinically occult micrometastasis present in secondary organs at primary diagnosis but not detectable even with high resolution imaging procedures. Sensitive and specific immunocytochemical and molecular assays enable the detection and characterization of disseminated tumor cells (DTC) at the single cell level in bone marrow (BM) as the common homing site of DTC and circulating tumor cells (CTC) in peripheral blood. Because of the high variability of results in DTC and CTC detection, there is an urgent need for standardized methods. In this review, we will focus on BM and present currently available methods for the detection and characterization of DTC. Furthermore, we will discuss data on the biology of DTC and the clinical relevance of DTC detection. While the prognostic impact of DTC in BM has clearly been shown for primary breast cancer patients, less is known about the clinical relevance of DTC in patients with other carcinomas. Current findings suggest that DTC are capable to survive chemotherapy and persist in a dormant nonproliferating state over years. To what extent these DTC have stem cell properties is subject of ongoing investigations. Further characterization is required to understand the biology of DTC and to identify new targets for improved risk prevention and tailoring of therapy. Our review will focus on breast, colon, lung, and prostate cancer as the main tumor entities in Europe and the United States.
TL;DR: This study is the first report to underline the potential role of RAS‐MAPK, PI (3)K network mutations on survival in colon cancers and the evaluation of its mutations could have clinical implications.
Abstract: The RAS-MAPK, PI (3)K signaling pathways form a network that play a central role in tumorigenesis. The BRAF, KRAS and PI3KCA genes code 3 partners of this network and have been found to be activated by mutation in colorectal cancer; these mutations lead to unrestricted cell growth. We evaluated the clinicopathological features and the prognosis of patients with activated-network colon cancers in a population-based study. A total of 586 colon adenocarcinomas were evaluated using sequencing for mutations of KRAS and PI3KCA, and allelic discrimination for mutation of BRAF. Clinicopathological characteristics were correlated to the risk of bearing a mutation of the network using logistic regression. Three-year survival rates were compared with the Log rank test. A multivariate survival analysis using the Cox model was performed. After adjustment for age and microsatellite instability, activation of the network by mutation of at least 1 of the 3 genes was significantly associated with female sex (p = 0.02) and proximal location (p < 0.001). Lower levels of 3-year survival were associated with activation of the network by mutation of at least 1 of the 3 genes (59.4 and 69.4%, respectively; p = 0.009). These results remained significant in a multivariate analysis adjusted for sex, age, location, stage and microsatellite instability (HR = 1.48; CI CI(95%) = [1.07-2.04]). Our study is the first report to underline the potential role of RAS-MAPK, PI (3)K network mutations on survival in colon cancers. Because of the role of this signaling network on anticancer agents, the evaluation of its mutations could have clinical implications.
TL;DR: The authors have demonstrated the diagnostic miRNA profile for HCC, and for the first time, identified the miR‐125b with predictive significance for H CC prognosis.
Abstract: MicroRNAs (miRNAs) are important gene regulators, which are often deregulated in cancers. In this study, the authors analyzed the microRNAs profiles of 78 matched cancer/noncanerous liver tissues from HCC patients and 10 normal liver tissues and found that 69 miRNAs were differentially expressed between hepatocellular carcinoma (HCC) and corresponding noncancerous liver tissues (N). Then the expressions of 8 differentially expressed miRNAs were validated by real time RT PCR. The set of differentially expressed miRNAs could distinctly classify HCC, N and normal liver tissues (NL). Moreover, some of these differentially expressed miRNAs were related to the clinical factors of HCC patients. Most importantly, Kaplan-Meier estimates and the log-rank test showed that high expression of hsa-miR-125b was correlated with good survival of HCC patients (hazard ratio, 1.787, 95% confidence interval, 1.020-3.133, p = 0.043). The transfection assay showed that overexpression of miR-125b in HCC cell line could obviously suppress the cell growth and phosporylation of Akt. In conclusion, the authors have demonstrated the diagnostic miRNA profile for HCC, and for the first time, identified the miR-125b with predictive significance for HCC prognosis.
TL;DR: A major finding was the consistently higher sensitivity but equal specificity of VILI compared with VIA, and some caution is warranted in the interpretation of observed accuracy measures, since a certain degree of gold standard misclassification cannot be excluded.
Abstract: Cervical cancer is the main cancer among women in sub-Saharan Africa, India and other parts of the developing world. Evaluation of screening performance of effective, feasible and affordable early detection and management methods is a public health priority. Five screening methods, naked eye visual inspection of the cervix uteri after application of diluted acetic acid (VIA), or Lugol's iodine (VILI) or with a magnifying device (VIAM), the Pap smear and human papillomavirus testing with the high-risk probe of the Hybrid Capture-2 assay (HC2), were evaluated in 11 studies in India and Africa. More than 58,000 women, aged 25-64 years, were tested with 2-5 screening tests and outcome verification was done on all women independent of the screen test results. The outcome was presence or absence of cervical intraepithelial neoplasia (CIN) of different degrees or invasive cervical cancer. Verification was based on colposcopy and histological interpretation of colposcopy-directed biopsies. Negative colposcopy was accepted as a truly negative outcome. VIA showed a sensitivity of 79% (95% CI 73-85%) and 83% (95% CI 77-89%), and a specificity of 85% (95% CI 81-89%) and 84% (95% CI 80-88%) for the outcomes CIN2+ or CIN3+, respectively. VILI was on average 10% more sensitive and equally specific. VIAM showed similar results as VIA. The Pap smear showed lowest sensitivity, even at the lowest cutoff of atypical squamous cells of undetermined significance (57%; 95% CI 38-76%) for CIN2+ but the specificity was rather high (93%; 95% CI 89-97%). The HC2-assay showed a sensitivity for CIN2+ of 62% (95% CI 56-68%) and a specificity of 94% (95% CI 92-95%). Substantial interstudy variation was observed in the accuracy of the visual screening methods. Accuracy of visual methods and cytology increased over time, whereas performance of HC2 was constant. Results of visual tests and colposcopy were highly correlated. This study was the largest ever done that evaluates the cross-sectional accuracy of screening tests for cervical cancer precursors in developing countries. The merit of the study was that all screened subjects were submitted to confirmatory investigations avoiding to verification bias. A major finding was the consistently higher sensitivity but equal specificity of VILI compared with VIA. Nevertheless, some caution is warranted in the interpretation of observed accuracy measures, since a certain degree of gold standard misclassification cannot be excluded. Because of the correlation between visual screening tests and colposcopy and a certain degree of over-diagnosis of apparent CIN2+ by study pathologists, it is possible that both sensitivity and specificity of VIA and VILI were overestimated. Gold standard verification error could also explain the surprisingly low sensitivity of HC2, which contrasts with findings from other studies.
TL;DR: Mir‐21 is a putative oncogenic microRNA in head and neck cancer and may be of interest as potential novel oncogenes and tumor suppressor genes in HNSCC.
Abstract: MicroRNAs (mirs) are small noncoding RNA molecules (~22 nucleotides) that regulate posttranscriptional gene expression. Currently, there has not been a comprehensive study of their role in primary head and neck squamous cell carcinoma (HNSCC). To determine the role of mirs in HNSCC, we screened for altered microRNA expression in HNSCC primary tissue and cell lines. We then further tested the functional impact of alterations of specific mirs. An initial screening of 4 primary HNSCC, 4 normal mucosal controls and 4 HNSCC cell lines was analyzed for mature microRNA expression by microarray. Significance was determined using significance analysis of microarrays (SAM). Nine microRNAs were found by SAM to be upregulated or downregulated in tumor tissue including mir-21, let-7, 18, 29c, 142-3p, 155, 146b (overexpressed) and 494 (underexpressed). Mir-21 was validated by qRT-PCR. Functional validation by growth assays was performed, further validating mir-21. Transfection of mir-21 into JHU-011 and JHU-012 cell lines showed a 39% increase in cell growth at 72 hr relative to controls (p < 0.05). Transfection of the inhibitor into JHU-O12 cell lines showed a 92% decrease in cell growth relative to controls at 72 hr (p < 0.05). In addition, flow cytometry analysis of JHU-012 cells 48 hr after mir-21 inhibitor transfection showed a statistically significant increase in cytochrome c release and increased apoptosis. These differentially expressed microRNAs may be of interest as potential novel oncogenes and tumor suppressor genes in HNSCC. Mir-21 is a putative oncogenic microRNA in head and neck cancer.
TL;DR: This is the first investigation describing the delivery of CRC screening protocols to various populations, and the work of the ICRCSN is enabling valuable information to be shared and a common nomenclature to be established.
Abstract: Although in its infancy, organized screening for colorectal cancer (CRC) in the general population is increasing at regional and national levels. Documenting and describing these initiatives is critical to identifying, sharing and promoting best practice in the delivery of CRC screening. Subsequently, the International Colorectal Cancer Screening Network (ICRCSN) was established in 2003 to promote best practice in the delivery of organized screening programs. The initial aim was to identify and document organized screening initiatives that commenced before May 2004. Each identified initiative was sent 1 questionnaire per screening modality: fecal occult blood test, flexible sigmoidoscopy or total colonoscopy. Information was collected on screening methodology, testing details and initiative status. In total, 35 organized initiatives were identified in 17 countries, including 10 routine population-based screening programs, 9 pilots and 16 research projects. Fecal occult blood tests were the most frequently used screening modality, and total colonoscopy was seldom used as a primary screening test. The eligible age for screening ranged from 40 years old to no upper limit; most initiatives included participants aged 50 to 64. Recruitment was usually done by a mailed invitation or during a visit to a family physician. In conclusion, this is the first investigation describing the delivery of CRC screening protocols to various populations. The work of the ICRCSN is enabling valuable information to be shared and a common nomenclature to be established.
TL;DR: The generation of 3 human monoclonal antibodies (named F8, B7 and D5), which recognize the same epitope of EDA, but which differ in terms of their dissociation constant to the human antigen.
Abstract: The alternatively spliced extra-domain B of fibronectin is one of the best characterized markers of tumor angiogenesis. Similarly, the extra-domain A (EDA), which can also be inserted in the fibronectin transcript by a mechanism of alternative splicing, has been shown to preferentially accumulate around new blood vessels in certain tumors, but this antigen has not been investigated so far as a target for antibody-based biomolecular intervention. We here describe the generation of 3 human monoclonal antibodies (named F8, B7 and D5), which recognize the same epitope of EDA, but which differ in terms of their dissociation constant to the human antigen (KD = 3.1, 16 and 17 nM, measured for monomeric preparations of the F8, B7 and D5 antibodies, respectively, in recombinant scFv format). When the 3 antibody fragments were cloned and expressed with a 5 amino acid linker, the 3 resulting homodimeric antibody preparations displayed comparable tumor: organ ratios in quantitative biodistribution studies, performed in immunocompetent 129SvEv mice, bearing subcutaneous syngeneic F9 murine tumors. The percent injected dose per gram (%ID/g) values in tumors 24 hr after intravenous injection were 9.3, 10.2 and 13 for F8, B7 and D5, respectively. The F8 antibody may serve as useful building block for the development of antibody-based targeted anti-cancer therapeutics. Preclinical and clinical investigations are facilitated by the fact that F8 recognizes the human and mouse antigen with comparable affinity, and by the observation that EDA over-expression is detectable not only in solid tumors, but also in hematological malignancies. © 2008 Wiley-Liss, Inc.
TL;DR: Excess second head and neck cancer risk was observed 10 years after diagnosis with lymphohaematopoietic cancers, and patterns were consistent with the notion that the pattern of cancer in survivors of head andneck cancer is dominated by the effect of tobacco smoking and alcohol drinking.
Abstract: The objective of the study was to assess the risk of second primary cancers (SPCs) following a primary head and neck cancer (oral cavity, pharynx and larynx) and the risk of head and neck cancer as a SPC. The present investigation is a multicenter study from 13 population-based cancer registries. The study population involved 99,257 patients with a first primary head and neck cancer and contributed 489,855 person-years of follow-up. To assess the excess risk of SPCs following head and neck cancers, we calculated standardized incidence ratios (SIRs) by dividing the observed numbers of SPCs by the expected number of cancers calculated from accumulated person-years and the age-, sex- and calendar period-specific first primary cancer incidence rates in each of the cancer registries. During the observation period, there were 10,826 cases of SPCs after head and neck cancer. For all cancer sites combined, the SIR of SPCs was 1.86 (95% CI = 1.83-1.90) and the 20-year cumulative risk was 36%. Lung cancer contributed to the highest proportion of the SPCs with a 20-year cumulative risk of 13%. Excess second head and neck cancer risk was observed 10 years after diagnosis with lymphohaematopoietic cancers. The most common SPC following a first primary head and neck cancer was lung cancer. However, the highest excess of SPCs was in the head and neck region. These patterns were consistent with the notion that the pattern of cancer in survivors of head and neck cancer is dominated by the effect of tobacco smoking and alcohol drinking.
TL;DR: It is shown here that miR‐221 is also induced by MYCN in neuroblastoma, and miRNA induction is reported to be a new mechanism of gene expression downregulation by Myc.
Abstract: MYCN amplification is a common feature of aggressive tumour biology in neuroblastoma. The MYCN transcription factor has been demonstrated to induce or repress expression of numerous genes. MicroRNAs (miRNA) are a recently discovered class of short RNAs that repress translation and promote mRNA degradation by sequence-specific interaction with mRNA. Here, we sought to analyse the role of MYCN in regulation of miRNA expression. Using a miRNA microarray containing 384 different miRNAs and a set of 160 miRNA real-time PCR assays to validate the microarray results, 7 miRNAs were identified that are induced by MYCN in vitro and are upregulated in primary neuroblastomas with MYCN amplification. Three of the seven miRNAs belong to the miR-106a and miR-17 clusters, which have previously been shown to be regulated by c-Myc. The miR-17–92 polycistron also acts as an oncogene in haematopoietic progenitor cells. We show here that miR-221 is also induced by MYCN in neuroblastoma. Previous studies have reported miR-221 to be overexpressed in several other cancer entities, but its regulation has never before been associated with Myc. We present evidence of miRNA dysregulation in neuroblastoma. Additionally, we report miRNA induction to be a new mechanism of gene expression downregulation by MYCN. © 2007 Wiley-Liss, Inc.
TL;DR: High serum levels of MMP‐9 and TIMP‐1 were associated with lymph node metastasis, higher tumor stage and lower relapse‐free and overall survival (OS) rates, and high tissue expression of TIMP-1 was associated with a lower OS rate.
Abstract: Tumor progression and metastasis contribute to the great majority of breast cancer deaths. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are thought to be involved in tumor progression and metastasis. Thus, we determined whether the expression of MMP-9 and TIMP-1 is associated with prognosis in breast cancer patients. We measured serum MMP-9 and TIMP-1 by enzyme-linked immunosorbent assay in 60 breast cancer patients, 18 benign breast disease patients and 15 healthy controls. We also evaluated the expression of MMP-9 and TIMP-1 protein and mRNA in paraffin-embedded tumor tissues from the 60 breast cancer patients by immunohistochemistry and in situ hybridization. We then correlated serum and tissue levels of MMP-9 and TIMP-1 in breast cancer samples and their expression with patients' clinicopathologic characteristics. We found that serum levels of MMP-9 and TIMP-1 were significantly higher in breast cancer patients than in benign breast disease and in healthy controls. High serum levels of MMP-9 and TIMP-1 were associated with lymph node metastasis, higher tumor stage and lower relapse-free and overall survival (OS) rates. Compared to low expression, high tissue expression of MMP-9 protein was associated with lymph node metastasis and higher tumor stage; and high tissue expression of TIMP-1 was associated with a lower OS rate. Our findings suggest that MMP-9 and TIMP-1 may further be evaluated as biomarkers for predicting progression and prognosis of breast cancer.
TL;DR: Both CIMp‐high and MSI‐high are inversely associated with LINE‐1 hypomethylation, suggesting that CIMP/MSI and genomic hypometHylation may represent different pathways to colorectal cancer.
Abstract: The CpG island methylator phenotype (CIMP) with widespread promoter CpG island methylation is a phenotype in colorectal cancer, associated with microsatellite instability (MSI) and BRAF mutation. Genome-wide hypomethylation may also play an important role in genomic instability. However, the relation between global DNA methylation level and methylation in individual CpG islands remains uncertain. Utilizing 869 population-based colorectal cancers, we measured long interspersed nucleotide element-1 (LINE-1) methylation level by Pyrosequencing, which correlates with global DNA methylation level. We quantified DNA methylation in 8 CIMP-specific promoters (CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3 and SOCS1) by real-time PCR (MethyLight technology). LINE-1 methylation levels in tumors were approximately normally distributed (mean, 61.4%; median, 62.3%; standard deviation, 9.6%). Among the 869 tumors, 128 (15%) were classified as CIMP-high (>or=6/8 methylated promoters). The mean LINE-1 methylation level was higher in CIMP-high tumors (65.1%, p < 0.0001) than non-CIMP-high tumors (60.7%), and higher in MSI-high tumors (64.7%, p < 0.0001) than non-MSI-high tumors (60.7%). When tumors were stratified by MSI/CIMP status, compared to non-MSI-high non-CIMP-high tumors (mean LINE-1 methylation level, 60.4%), the mean LINE-1 methylation level was higher in MSI-high CIMP-high (64.8%, p < 0.0001), MSI-high non-CIMP-high (64.6%, p = 0.03) and non-MSI-high CIMP-high tumors (66.1%, p = 0.0003). In addition, 18q loss of heterozygosity in non-MSI-high tumors was correlated with LINE-1 hypomethylation (p = 0.004). In conclusion, both CIMP-high and MSI-high are inversely associated with LINE-1 hypomethylation, suggesting that CIMP/MSI and genomic hypomethylation may represent different pathways to colorectal cancer. Our data also support a possible link between global hypomethylation and chromosomal instability.
TL;DR: The mitochondria are the major target for the induction of apoptosis by vitamin E isomers and analogs and that the various signaling pathways regulated by these agents are likely to contribute towards maximizing the intrinsic pathway of apoptOS triggered initially by the mitochondria.
Abstract: Current observations in the literature suggest that vitamin E may be a suitable candidate for the adjuvant treatment of cancer. Even though historically most research focused on α-tocopherol, more recent evidence suggests that the other isomers of vitamin E (β-, γ- and δ-tocopherols and α-, β-, γ- and δ-tocotrienols) differ in their proapoptotic potencies. The main focus of this communication is the current understanding of the molecular mechanisms regulated by vitamin E isomers and their analogs during the induction of apoptosis. This review highlights that the mitochondria are the major target for the induction of apoptosis by vitamin E isomers and analogs and that the various signaling pathways regulated by these agents are likely to contribute towards maximizing the intrinsic pathway of apoptosis triggered initially by the mitochondria. Overall, the presentation of recent studies from the literature in this communication allows the drawing of the following important conclusions: (i) no direct link exists between the antioxidant activity of each isomer/derivative and proapoptotic potency, (ii) tocotrienols are more effective proapoptotic agents than tocopherols, (iii) synthetic modifications of the naturally occurring compounds may improve their apoptotic potency and (iv) vitamin E isomers and derivatives regulate caspase-independent pathways of apoptosis. The latter combined with the evidence presented in this review regarding the additive or synergistic anticarcinogenic effects obtained when vitamin E analogs are used in combination with other cancer chemotherapeutic agents, supports further research to design the most promising vitamin E derivatives and clinically test them in adjuvant chemotherapeutic treatments. © 2008 Wiley-Liss, Inc.
TL;DR: High BMI was the lifestyle risk factor that most consistently modified breast cancer prognosis in this study, and no significant relationship with survival after breast cancer emerged for several other major lifestyle factors, including physical activity, alcohol drinking, exogenous hormones use and fat intake.
Abstract: A few lifestyle characteristics before cancer diagnosis have been suggested to modify the prognosis of breast cancer. Follow-up information from 1,453 women with incident invasive breast cancer, diagnosed between 1991 and 1994 and interviewed within the framework of an Italian multicenter case-control study, was used to assess the effect of obesity and of a large spectrum of other factors on breast cancer mortality. Five hundred and three deaths, including 398 breast cancer deaths, were identified. Hazard ratios (HR) for all-cause and breast cancer mortality and corresponding 95% confidence intervals (CI), were calculated using Cox proportional hazards models and adjusted for age and breast cancer characteristics (stage and receptor status). Increased risk of death for breast cancer emerged for body mass index (BMI) >/= 30 kg/m(2) (HR = 1.38; 95% CI: 1.02-1.86), compared to /= 0.85 (HR = 1.27; 95% CI: 0.98-1.64), compared to /=30 and high WHR (>/=0.85), compared to women with BMI /=55 years of age, whereas it was stronger in women with I-II stage than III-IV stage breast cancer. Low vegetable and fruit consumption and current or past smoking were also associated to marginally worse breast cancer survival. No significant relationship with survival after breast cancer emerged for several other major lifestyle factors, including physical activity, alcohol drinking, exogenous hormones use and fat intake. High BMI was the lifestyle risk factor that most consistently modified breast cancer prognosis in our study.
TL;DR: A sub‐population of cells displaying features normally attributed to stem cells was identified within the breast cancer cell line MCF‐7, and α6‐integrin is shown as a potential therapeutic target aimed at tumour‐generating subsets of breast cancer cells.
Abstract: The identification of mammary epithelial stem cells raises the hypothesis that these cells may be crucial in the pathogenesis of breast cancer. To further support this, a highly tumourigenic sub-population of cancer cells has recently been identified in primary and metastatic breast cancer samples. In this study, a sub-population of cells displaying features normally attributed to stem cells was identified within the breast cancer cell line MCF-7. This sub-population is capable of growth in anchorage-independent conditions as spherical organoids, displays resistance to proapoptotic agents and significantly greater tumourigenicity than its parental line, with as few as 1,000 cells able to form tumours in immunodeficient mice. Cells within this sub-population can be enriched by serial passages in anchorage-independence, and are characterized by over-expression of the adhesion molecule 6-integrin. Alpha-6 integrin proves to be required for the growth and survival of these cells, as the knockdown of ITGA6 causes mammosphere-derived cells to lose their ability to grow as mammospheres and abrogates their tumourigenicity in mice. These findings support the existence of a highly tumourigenic sub-population in breast cancer cells. Furthermore, it shows 6-integrin as a potential therapeutic target aimed at tumour-generating subsets of breast cancer cells.
TL;DR: Novel high‐throughput, quantitative assays for the detection of DNA methylation or histone tail modifications are applied, to search for alterations in the lung cancer genome and will identify novel cancer‐related genes that may become attractive targets for treatment, provide new insight into the biology of lung cancers, and could also become useful biomarkers for the early detection of lung cancer in sputum, or may be used as prognostic markers.
Abstract: Lung cancer is the leading cause of cancer-related death and thus a major health problem. The efficiency of current treatment modalities for lung cancer depends strongly on the time of diagnosis, with better chances of survival if a tumor has been detected at an early stage. Thus, there is an urgent need for rapid and efficient early detection methods. Biomarkers represent a possible alternative to current, rather expensive, screening tools such as spiral computer tomography (CT), or may allow the identification of high risk groups for whom screening would be cost efficient. Although most lung cancers are the consequence of smoking, a substantial fraction of molecular-epidemiological studies point to high-prevalence, low-penetrance genetic polymorphisms as modifiers of environmental lung cancer risk. In the past the genomics field has also made significant advances in identifying genetic lesions that can now be harvested with the goal of identifying novel biomarkers for lung cancer. Furthermore, the importance of epigenetic changes that occur during lung cancer development has been reported, but has been underestimated in the past. Novel high-throughput, quantitative assays for the detection of DNA methylation or histone tail modifications are now applied, to search for alterations in the lung cancer genome and will identify novel cancer-related genes that may become attractive targets for treatment, provide new insight into the biology of lung cancers, and could also become useful biomarkers for the early detection of lung cancer in sputum, or may be used as prognostic markers. Thus, an integrative approach in lung cancer research combining epidemiological, genetic and epigenetic information becomes an important concept for the future.